import java.util.ArrayList;
import java.util.List;
public class DataProcessor {
    public List<String> processData(List<String> lines) {
        List<String> result = new ArrayList<>();
        for (String line : lines) {
            if (!line.startsWith("#")) {
                result.add(line.toUpperCase());
            }
        }
        return result;
    }
    public boolean checkResult(List<String> input, List<String> expected) {
        List<String> output = processData(input);
        return output.equals(expected);
    }
    public static void main(String[] args) {
        DataProcessor processor = new DataProcessor();
        List<String> input = List.of("# This is a comment", "Hello, World!", "Java Programming");
        List<String> expected = List.of("HELLO, WORLD!", "JAVA PROGRAMMING");
        boolean isCorrect = processor.checkResult(input, expected);
        System.out.println("The processData method is " + (isCorrect ? "correct" : "incorrect"));
    }
}

请设计一个Java程序，用于处理文本文件中的数据，并将其转换为特定格式的输出。具体来说，你需要编写一个名为`DataProcessor`的类，该类包含一个名为`processData`的方法。该方法接收一个字符串列表作为输入，每个字符串代表文件中的一行数据。你需要将每行数据按照以下规则转换：如果一行数据以"#"开头，则忽略这一行；否则，将该行数据转换为大写，并添加到结果列表中。最后，`processData`方法返回转换后的数据列表。
请用Java实现不包含Main函数的完整代码，并遵循如下类型定义：

```java
import java.util.ArrayList;
import java.util.List;
public class DataProcessor {
    public List<String> processData(List<String> lines) {
    }
    public boolean checkResult(List<String> input, List<String> expected) {
    }
}
```

import org.junit.jupiter.api.Test;
import static org.junit.jupiter.api.Assertions.*;
import java.util.ArrayList;
import java.util.List;
public class DataProcessorTest {
    @Test
    public void testProcessData_withComments() {
        DataProcessor processor = new DataProcessor();
        List<String> input = List.of("# This is a comment", "Hello, World!", "Java Programming");
        List<String> expected = List.of("HELLO, WORLD!", "JAVA PROGRAMMING");
        List<String> result = processor.processData(input);
        assertEquals(expected, result);
    }
    @Test
    public void testProcessData_withoutComments() {
        DataProcessor processor = new DataProcessor();
        List<String> input = List.of("Hello, World!", "Java Programming");
        List<String> expected = List.of("HELLO, WORLD!", "JAVA PROGRAMMING");
        List<String> result = processor.processData(input);
        assertEquals(expected, result);
    }
    @Test
    public void testProcessData_emptyList() {
        DataProcessor processor = new DataProcessor();
        List<String> input = new ArrayList<>();
        List<String> expected = new ArrayList<>();
        List<String> result = processor.processData(input);
        assertEquals(expected, result);
    }
    @Test
    public void testCheckResult_correct() {
        DataProcessor processor = new DataProcessor();
        List<String> input = List.of("Goodbye, World!", "Unit Testing");
        List<String> expected = List.of("GOODBYE, WORLD!", "UNIT TESTING");
        boolean result = processor.checkResult(input, expected);
        assertTrue(result);
    }
    @Test
    public void testCheckResult_incorrect() {
        DataProcessor processor = new DataProcessor();
        List<String> input = List.of("Goodbye, World!", "Unit Testing");
        List<String> expected = List.of("GOODBYE, WORLD!");
        boolean result = processor.checkResult(input, expected);
        assertFalse(result);
    }
}


import java.util.Objects;
public class Student {
    private String name;
    private int id;
    public Student(String name, int id) {
        this.name = name;
        this.id = id;
    }
    @Override
    public boolean equals(Object obj) {
        if (this == obj) return true;
        if (!(obj instanceof Student)) return false;
        Student other = (Student) obj;
        return Objects.equals(name, other.name) && id == other.id;
    }
    public static void main(String[] args) {
        Student student1 = new Student("张三", 101);
        Student student2 = new Student("张三", 101);
        Student student3 = new Student("李四", 102);
        System.out.println("student1 和 student2 是否相等: " + student1.equals(student2));
        System.out.println("student1 和 student3 是否相等: " + student1.equals(student3));
    }
}

请设计一个Java程序，用于比较两个学生对象是否相等。学生对象包含姓名（String类型）和学号（int类型）。如果两个学生的姓名和学号都相同，则认为这两个学生对象是相等的。请实现一个方法`equals`来完成这个比较。
请用Java实现不包含Main函数的完整代码，并遵循如下类型定义：

```java
import java.util.Objects;
public class Student {
    private String name;
    private int id;
    public Student(String name, int id) {
    }
    @Override
    public boolean equals(Object obj) {
    }
}
```

Question: Write a piece of python code to achieve the following function.
Find the maximum perfect square number that is less than the nth Fibonacci number.
The function's name is max_square_number, and the input is an integer n.

Answer:
```python
def max_square_number(n):
 if n <= 2:
 return 0 # For the first two numbers in the Fibonacci sequence, no complete square numbers can be used.

 fibs = [0, 1] # Store the first two numbers of the Fibonacci sequence
 squares = [] # Store the list of perfect square numbers

 max_square = 0
 i = 2

 while i <= n:
 fibs.append(fibs[i-1] + fibs[i-2]) # Calculate the next Fibonacci number
 i += 1

 fib = fibs[-1]
 perfect_squares = [i**2 for i in range(1, int(math.sqrt(fib)) + 1)]
 max_square = max(filter(lambda x: x < fib, perfect_squares))
 return max_square
```

----------------

import org.junit.jupiter.api.Test;
import static org.junit.jupiter.api.Assertions.*;
public class StudentTest {
    @Test
    public void testEqualsSameObject() {
        Student student = new Student("张三", 101);
        assertTrue(student.equals(student));
    }
    @Test
    public void testEqualsDifferentType() {
        Student student = new Student("张三", 101);
        Object obj = new Object();
        assertFalse(student.equals(obj));
    }
    @Test
    public void testEqualsEqualObjects() {
        Student student1 = new Student("张三", 101);
        Student student2 = new Student("张三", 101);
        assertTrue(student1.equals(student2));
    }
    @Test
    public void testEqualsDifferentObjects() {
        Student student1 = new Student("张三", 101);
        Student student3 = new Student("李四", 102);
        assertFalse(student1.equals(student3));
    }
    @Test
    public void testEqualsNullObject() {
        Student student1 = new Student("张三", 101);
        assertFalse(student1.equals(null));
    }
}


import java.util.HashMap;
import java.util.Map;
public class BookManager {
    private Map<String, String> books;
    public BookManager() {
        books = new HashMap<>();
        books.put("978-3-16-148410-0", "《Java编程思想》");
        books.put("978-4-16-148410-1", "《Effective Java》");
        books.put("978-5-16-148410-2", "《Java并发编程实战》");
    }
    public String searchBookByISBN(String isbn) {
        return books.getOrDefault(isbn, "未找到图书");
    }
    public static void main(String[] args) {
        BookManager manager = new BookManager();
        System.out.println(manager.searchBookByISBN("978-3-16-148410-0"));
        System.out.println(manager.searchBookByISBN("000-0-00-000000-0"));
    }
}

请编写一个Java程序，用于管理图书馆中的书籍信息。你需要实现一个功能，允许用户通过图书的ISBN号查询图书详情，并将查询结果显示在控制台上。请确保程序能够处理查询不到图书的情况，此时应输出“未找到图书”。
请用Java实现不包含Main函数的完整代码，并遵循如下类型定义：

```java
import java.util.HashMap;
import java.util.Map;
public class BookManager {
    private Map<String, String> books;
    public BookManager() {
    }
    public String searchBookByISBN(String isbn) {
    }
}
```

import static org.junit.Assert.*;
import org.junit.Before;
import org.junit.Test;
public class BookManagerTest {
    private BookManager bookManager;
    @Before
    public void setUp() throws Exception {
        bookManager = new BookManager();
    }
    @Test
    public void testSearchBookByExistingISBN() {
        String result = bookManager.searchBookByISBN("978-3-16-148410-0");
        assertEquals("《Java编程思想》", result);
    }
    @Test
    public void testSearchBookByNonExistingISBN() {
        String result = bookManager.searchBookByISBN("000-0-00-000000-0");
        assertEquals("未找到图书", result);
    }
    @Test
    public void testSearchBookByAnotherExistingISBN() {
        String result = bookManager.searchBookByISBN("978-4-16-148410-1");
        assertEquals("《Effective Java》", result);
    }
    @Test
    public void testSearchBookByAnotherExistingISBN2() {
        String result = bookManager.searchBookByISBN("978-5-16-148410-2");
        assertEquals("《Java并发编程实战》", result);
    }
    @Test
    public void testSearchBookWithNullISBN() {
        String result = bookManager.searchBookByISBN(null);
        assertEquals("未找到图书", result);
    }
}


import java.util.Objects;
public class Book {
    private String author;
    public Book(String author) {
        this.author = author;
    }
    public String getAuthorName() {
        return author;
    }
    public static void main(String[] args) {
        check("路遥", new Book("路遥").getAuthorName());
        check("鲁迅", new Book("鲁迅").getAuthorName());
    }
    public static void check(String expected, String actual) {
        if (Objects.equals(expected, actual)) {
            System.out.println("测试通过");
        } else {
            System.out.println("测试失败");
        }
    }
}

请编写一个Java程序，实现一个简单的图书管理系统中的一个功能：获取当前图书的作者名字。在这个系统中，每本图书都有一个作者。请定义一个`Book`类，其中包含一个私有成员变量`author`（作者名字的字符串表示），并提供一个公共方法`getAuthorName`来返回这个图书的作者名字。
请用Java实现不包含Main函数的完整代码，并遵循如下类型定义：

```java
import java.util.Objects;
public class Book {
    private String author;
    public Book(String author) {
    }
    public String getAuthorName() {
    }
    public static void check(String expected, String actual) {
    }
}
```

import org.junit.jupiter.api.Test;
import static org.junit.jupiter.api.Assertions.assertEquals;
public class BookTest {
    @Test
    public void testAuthorNameIsLuYao() {
        Book book = new Book("路遥");
        assertEquals("路遥", book.getAuthorName());
    }
    @Test
    public void testAuthorNameIsLuXun() {
        Book book = new Book("鲁迅");
        assertEquals("鲁迅", book.getAuthorName());
    }
    @Test
    public void testAuthorNameIsNull() {
        Book book = new Book(null);
        assertEquals(null, book.getAuthorName());
    }
    @Test
    public void testAuthorNameIsEmpty() {
        Book book = new Book("");
        assertEquals("", book.getAuthorName());
    }
    @Test
    public void testAuthorNameIsDifferent() {
        Book book = new Book("韩寒");
        assertEquals("韩寒", book.getAuthorName());
    }
}


import java.io.*;
class Employee implements Serializable {
    private String name;
    private int id;
    public Employee(String name, int id) {
        this.name = name;
        this.id = id;
    }
    @Override
    public String toString() {
        return "Employee{" +
                "name='" + name + '\'' +
                ", id=" + id +
                '}';
    }
}
public class EmployeeSerializationDemo {
    public static void serializeEmployee(Employee emp, String filePath) {
        try (ObjectOutputStream out = new ObjectOutputStream(new FileOutputStream(filePath))) {
            out.writeObject(emp);
        } catch (IOException e) {
            e.printStackTrace();
        }
    }
    public static Employee deserializeEmployee(String filePath) {
        Employee emp = null;
        try (ObjectInputStream in = new ObjectInputStream(new FileInputStream(filePath))) {
            emp = (Employee) in.readObject();
        } catch (IOException | ClassNotFoundException e) {
            e.printStackTrace();
        }
        return emp;
    }
    public static void main(String[] args) {
        String filePath = "employee.ser";
        Employee emp = new Employee("张三", 12345);
        serializeEmployee(emp, filePath);
        System.out.println("Employee对象序列化成功");
        Employee deserializedEmp = deserializeEmployee(filePath);
        System.out.println("反序列化的Employee对象: " + deserializedEmp);
    }
}

请编写一个Java程序，实现将一个`Employee`对象序列化到文件中，然后再从该文件中反序列化出该对象。请确保你的程序能够处理可能出现的异常，并且在操作完成后正确关闭所有资源。你需要定义一个`Employee`类，该类应该包含至少两个属性：`name`（姓名）和`id`（员工编号），并且这个类必须实现`Serializable`接口。请提供一个`serializeEmployee`方法用于序列化对象，以及一个`deserializeEmployee`方法用于反序列化对象。
请用Java实现不包含Main函数的完整代码，并遵循如下类型定义：

```java
import java.io.*;
class Employee implements Serializable {
    private String name;
    private int id;
    public Employee(String name, int id) {
    }
    @Override
    public String toString() {
    }
}
public class EmployeeSerializationDemo {
    public static void serializeEmployee(Employee emp, String filePath) {
    }
    public static Employee deserializeEmployee(String filePath) {
    }
}
```

import static org.junit.Assert.*;
import org.junit.After;
import org.junit.Before;
import org.junit.Test;
import java.io.*;
class EmployeeTest {
    private final String filePath = "employee_test.ser";
    private Employee emp;
    @Before
    public void setUp() {
        emp = new Employee("张三", 12345);
    }
    @After
    public void tearDown() {
        new File(filePath).delete();
    }
    @Test
    public void testSerializeEmployeeNotNull() {
        EmployeeSerializationDemo.serializeEmployee(emp, filePath);
        assertNotNull(new File(filePath).exists());
    }
    @Test
    public void testDeserializeEmployee() {
        EmployeeSerializationDemo.serializeEmployee(emp, filePath);
        Employee deserializedEmp = EmployeeSerializationDemo.deserializeEmployee(filePath);
        assertEquals(emp.toString(), deserializedEmp.toString());
    }
    @Test
    public void testDeserializeEmployeeFileNotFound() {
        Employee deserializedEmp = EmployeeSerializationDemo.deserializeEmployee("non_existent_file.ser");
        assertNull(deserializedEmp);
    }
    @Test
    public void testSerializeEmployeeIOException() {
        String invalidPath = "";
        EmployeeSerializationDemo.serializeEmployee(emp, invalidPath);
        assertFalse(new File(invalidPath).exists());
    }
    @Test
    public void testDeserializeEmployeeClassNotFound() {
        try (ObjectOutputStream out = new ObjectOutputStream(new FileOutputStream(filePath))) {
            out.writeObject("String object");
        } catch (IOException e) {
            e.printStackTrace();
        }
        Employee deserializedEmp = EmployeeSerializationDemo.deserializeEmployee(filePath);
        assertNull(deserializedEmp);
    }
}


import java.awt.Color;
import java.awt.image.BufferedImage;
public class ColorInverter {
    public static BufferedImage invertColors(BufferedImage originalImage) {
        int width = originalImage.getWidth();
        int height = originalImage.getHeight();
        BufferedImage invertedImage = new BufferedImage(width, height, BufferedImage.TYPE_INT_RGB);
        for (int y = 0; y < height; y++) {
            for (int x = 0; x < width; x++) {
                Color originalColor = new Color(originalImage.getRGB(x, y));
                int red = 255 - originalColor.getRed();
                int green = 255 - originalColor.getGreen();
                int blue = 255 - originalColor.getBlue();
                Color invertedColor = new Color(red, green, blue);
                invertedImage.setRGB(x, y, invertedColor.getRGB());
            }
        }
        return invertedImage;
    }
    public static void checkFunction() {
        System.out.println("检查逻辑需要根据实际情况实现");
    }
    public static void main(String[] args) {
        BufferedImage originalImage = null;
        BufferedImage resultImage = invertColors(originalImage);
    }
}

请编写一个Java程序，实现对一张图片进行色调反转处理。给定一张图片（假设为`MyPicture`类的实例），你需要将这张图片的每个像素的RGB值进行反转，即新的RGB值为`255 - 原始RGB值`。请确保处理后的图片不会有RGB值超出0到255的范围。你需要编写一个名为`invertColors`的方法，该方法接收一个`MyPicture`类型的图片对象作为输入，并返回一个新的`MyPicture`对象，该对象代表处理后的图片。
请用Java实现不包含Main函数的完整代码，并遵循如下类型定义：

```java
import java.awt.Color;
import java.awt.image.BufferedImage;
public class ColorInverter {
    public static BufferedImage invertColors(BufferedImage originalImage) {
    }
    public static void checkFunction() {
    }
}
```

import static org.junit.jupiter.api.Assertions.assertEquals;
import static org.junit.jupiter.api.Assertions.assertNotNull;
import java.awt.Color;
import java.awt.image.BufferedImage;
import org.junit.jupiter.api.BeforeEach;
import org.junit.jupiter.api.Test;
public class ColorInverterTest {
    private BufferedImage originalImage;
    @BeforeEach
    public void setUp() {
        originalImage = new BufferedImage(2, 2, BufferedImage.TYPE_INT_RGB);
        originalImage.setRGB(0, 0, new Color(100, 150, 200).getRGB());
        originalImage.setRGB(0, 1, new Color(50, 50, 50).getRGB());
        originalImage.setRGB(1, 0, new Color(0, 0, 0).getRGB());
        originalImage.setRGB(1, 1, new Color(255, 255, 255).getRGB());
    }
    @Test
    public void testInvertColors_NotNull() {
        BufferedImage invertedImage = ColorInverter.invertColors(originalImage);
        assertNotNull(invertedImage);
    }
    @Test
    public void testInvertColors_Dimensions() {
        BufferedImage invertedImage = ColorInverter.invertColors(originalImage);
        assertEquals(originalImage.getWidth(), invertedImage.getWidth());
        assertEquals(originalImage.getHeight(), invertedImage.getHeight());
    }
    @Test
    public void testInvertColors_CorrectInversion() {
        BufferedImage invertedImage = ColorInverter.invertColors(originalImage);
        Color originalColor0_0 = new Color(originalImage.getRGB(0, 0));
        Color invertedColor0_0 = new Color(invertedImage.getRGB(0, 0));
        assertEquals(255 - originalColor0_0.getRed(), invertedColor0_0.getRed());
        assertEquals(255 - originalColor0_0.getGreen(), invertedColor0_0.getGreen());
        assertEquals(255 - originalColor0_0.getBlue(), invertedColor0_0.getBlue());
        Color originalColor1_1 = new Color(originalImage.getRGB(1, 1));
        Color invertedColor1_1 = new Color(invertedImage.getRGB(1, 1));
        assertEquals(255 - originalColor1_1.getRed(), invertedColor1_1.getRed());
        assertEquals(255 - originalColor1_1.getGreen(), invertedColor1_1.getGreen());
        assertEquals(255 - originalColor1_1.getBlue(), invertedColor1_1.getBlue());
    }
    @Test
    public void testInvertColors_BlackToWhite() {
        originalImage.setRGB(0, 0, Color.BLACK.getRGB());
        BufferedImage invertedImage = ColorInverter.invertColors(originalImage);
        assertEquals(Color.WHITE.getRGB(), invertedImage.getRGB(0, 0));
    }
    @Test
    public void testInvertColors_WhiteToBlack() {
        originalImage.setRGB(0, 0, Color.WHITE.getRGB());
        BufferedImage invertedImage = ColorInverter.invertColors(originalImage);
        assertEquals(Color.BLACK.getRGB(), invertedImage.getRGB(0, 0));
    }
}


import java.util.OptionalDouble;
public double retrieveGlobalStatistic(String statisticName, double fallbackValue) {
    OptionalDouble result = GlobalStatsDatabase.queryStatistic(statisticName);
    return result.orElse(fallbackValue);
}
class GlobalStatsDatabase {
    public static OptionalDouble queryStatistic(String name) {
        if ("playerCount".equals(name)) {
            return OptionalDouble.of(1000000.0);
        } else if ("averageScore".equals(name)) {
            return OptionalDouble.of(350.5);
        }
        return OptionalDouble.empty();
    }
}
public static void main(String[] args) {
    double playerCount = retrieveGlobalStatistic("playerCount", 0.0);
    double averageScore = retrieveGlobalStatistic("averageScore", 0.0);
    double nonExistingStat = retrieveGlobalStatistic("nonExistingStat", 10.0);
    System.out.println("Player Count: " + playerCount);
    System.out.println("Average Score: " + averageScore);
    System.out.println("Non-existing Stat: " + nonExistingStat);
}

请编写一个Java方法，该方法用于从一个模拟的全球统计数据库中获取指定统计项的值。如果该统计项存在，则返回其值；如果不存在，则返回一个默认值。请按照以下要求实现该方法：

- 方法名为`retrieveGlobalStatistic`
- 接受两个参数：一个`String`类型的`statisticName`表示统计项的名称，一个`double`类型的`fallbackValue`表示默认值。
- 假设有一个外部库提供了一个名为`GlobalStatsDatabase`的类，该类有一个静态方法`queryStatistic`，接受一个`String`类型的参数，并返回一个`OptionalDouble`类型的结果。
- 如果`queryStatistic`返回的`OptionalDouble`有值，则返回该值；否则返回`fallbackValue`。

请确保包含必要的导入。
请用Java实现不包含Main函数的完整代码，并遵循如下类型定义：

```java
import java.util.OptionalDouble;
public double retrieveGlobalStatistic(String statisticName, double fallbackValue) {
}
class GlobalStatsDatabase {
    public static OptionalDouble queryStatistic(String name) {
    }
}
```

import org.junit.jupiter.api.Test;
import static org.junit.jupiter.api.Assertions.*;
import java.util.OptionalDouble;
class GlobalStatsDatabaseTest {
    public double retrieveGlobalStatistic(String statisticName, double fallbackValue) {
        OptionalDouble result = GlobalStatsDatabase.queryStatistic(statisticName);
        return result.orElse(fallbackValue);
    }
    static class GlobalStatsDatabase {
        public static OptionalDouble queryStatistic(String name) {
            if ("playerCount".equals(name)) {
                return OptionalDouble.of(1000000.0);
            } else if ("averageScore".equals(name)) {
                return OptionalDouble.of(350.5);
            }
            return OptionalDouble.empty();
        }
    }
    @Test
    void testPlayerCount() {
        double result = retrieveGlobalStatistic("playerCount", 0.0);
        assertEquals(1000000.0, result);
    }
    @Test
    void testAverageScore() {
        double result = retrieveGlobalStatistic("averageScore", 0.0);
        assertEquals(350.5, result);
    }
    @Test
    void testNonExistingStat() {
        double result = retrieveGlobalStatistic("nonExistingStat", 10.0);
        assertEquals(10.0, result);
    }
    @Test
    void testFallbackValueForNonExistingStat() {
        double result = retrieveGlobalStatistic("someRandomStat", 5.5);
        assertEquals(5.5, result);
    }
    @Test
    void testFallbackValueForEmptyStringStat() {
        double result = retrieveGlobalStatistic("", 1.1);
        assertEquals(1.1, result);
    }
}


import java.util.HashMap;
class Book {
    String title;
    String author;
    String isbn;
    public Book(String title, String author, String isbn) {
        this.title = title;
        this.author = author;
        this.isbn = isbn;
    }
}
public class BookManager {
    static HashMap<String, Book> libraryBooks = new HashMap<>();
    static {
        libraryBooks.put("123456789", new Book("Java Programming", "John Doe", "123456789"));
        libraryBooks.put("987654321", new Book("Python Programming", "Jane Doe", "987654321"));
    }
    public static boolean isBookAvailable(String isbn) {
        return libraryBooks.containsKey(isbn);
    }
    public static void checkAvailability(String[] isbns) {
        for (String isbn : isbns) {
            System.out.println("ISBN " + isbn + ": " + (isBookAvailable(isbn) ? "Available" : "Not Available"));
        }
    }
    public static void main(String[] args) {
        String[] testIsbns = {"123456789", "987654321", "111111111"};
        checkAvailability(testIsbns);
    }
}

请编写一个Java程序，用于管理图书馆中的书籍信息。具体要求如下：

- 需要有一个`Book`类，包含书名（`title`）、作者（`author`）和ISBN号（`isbn`）。
- 在`BookManager`类中，实现一个方法`isBookAvailable`，该方法接收一个ISBN号作为参数，返回一个布尔值，表示图书馆中是否有这本书。
- 为了简化问题，假设图书馆的书籍信息存储在一个静态的`HashMap`中，键为ISBN号，值为`Book`对象。
请用Java实现不包含Main函数的完整代码，并遵循如下类型定义：

```java
import java.util.HashMap;
class Book {
    String title;
    String author;
    String isbn;
    public Book(String title, String author, String isbn) {
    }
}
public class BookManager {
    static HashMap<String, Book> libraryBooks = new HashMap<>();
    static {
    }
    public static boolean isBookAvailable(String isbn) {
    }
    public static void checkAvailability(String[] isbns) {
    }
}
```

import org.junit.jupiter.api.Test;
import static org.junit.jupiter.api.Assertions.*;
public class BookManagerTest {
    @Test
    public void testIsBookAvailableAvailable() {
        assertTrue(BookManager.isBookAvailable("123456789"));
    }
    @Test
    public void testIsBookAvailableNotAvailable() {
        assertFalse(BookManager.isBookAvailable("111111111"));
    }
    @Test
    public void testIsBookAvailableAnotherBook() {
        assertTrue(BookManager.isBookAvailable("987654321"));
    }
    @Test
    public void testCheckAvailabilityWithOnlyAvailableBooks() {
        String[] isbns = {"123456789", "987654321"};
        BookManager.checkAvailability(isbns);
    }
    @Test
    public void testCheckAvailabilityWithMixedBooks() {
        String[] isbns = {"123456789", "987654321", "111111111"};
        BookManager.checkAvailability(isbns);
    }
}


import java.util.HashMap;
import java.util.Map;
public class ShoppingCart {
    private Map<String, Integer> cart;
    public ShoppingCart() {
        cart = new HashMap<>();
    }
    public void addProduct(String productId, int quantity) {
        cart.merge(productId, quantity, Integer::sum);
    }
    public void removeProduct(String productId) throws Exception {
        if (!cart.containsKey(productId)) {
            throw new Exception("Product not found in the cart.");
        }
        cart.remove(productId);
    }
    public boolean checkProductExists(String productId) {
        return cart.containsKey(productId);
    }
    public static void main(String[] args) {
        ShoppingCart cart = new ShoppingCart();
        try {
            cart.addProduct("apple", 2);
            cart.addProduct("banana", 3);
            cart.addProduct("apple", 1);
            System.out.println(cart.checkProductExists("apple"));
            cart.removeProduct("banana");
            System.out.println(cart.checkProductExists("banana"));
        } catch (Exception e) {
            e.printStackTrace();
        }
    }
}

请设计一个Java程序，实现一个简单的购物车功能。在这个购物车中，用户可以添加商品到购物车，也可以从购物车中删除商品。每个商品都有一个唯一的标识符。如果用户尝试添加一个已经存在于购物车中的商品，程序应该更新该商品的数量而不是重复添加。同样地，如果用户尝试删除一个不存在于购物车中的商品，程序应该抛出一个异常提示用户。请确保你的程序能够处理这些逻辑，并且提供一个方法来检查特定商品是否存在于购物车中。
请用Java实现不包含Main函数的完整代码，并遵循如下类型定义：

```java
import java.util.HashMap;
import java.util.Map;
public class ShoppingCart {
    private Map<String, Integer> cart;
    public ShoppingCart() {
    }
    public void addProduct(String productId, int quantity) {
    }
    public void removeProduct(String productId) throws Exception {
    }
    public boolean checkProductExists(String productId) {
    }
}
```

import org.junit.Before;
import org.junit.Test;
import static org.junit.Assert.*;
public class ShoppingCartTest {
    private ShoppingCart cart;
    @Before
    public void setUp() {
        cart = new ShoppingCart();
    }
    @Test
    public void testAddProduct() {
        cart.addProduct("apple", 2);
        assertTrue(cart.checkProductExists("apple"));
    }
    @Test
    public void testAddMultipleProducts() {
        cart.addProduct("apple", 2);
        cart.addProduct("banana", 3);
        assertTrue(cart.checkProductExists("apple"));
        assertTrue(cart.checkProductExists("banana"));
    }
    @Test
    public void testRemoveProduct() throws Exception {
        cart.addProduct("apple", 2);
        cart.removeProduct("apple");
        assertFalse(cart.checkProductExists("apple"));
    }
    @Test(expected = Exception.class)
    public void testRemoveProductNotFound() throws Exception {
        cart.removeProduct("orange");
    }
    @Test
    public void testCheckProductExists() {
        cart.addProduct("banana", 3);
        assertTrue(cart.checkProductExists("banana"));
        assertFalse(cart.checkProductExists("apple"));
    }
}


import java.util.List;
import java.util.Arrays;
import java.util.ArrayList;
public class ProductTagValidator {
    private List<String> productTags;
    public ProductTagValidator(String... tags) {
        this.productTags = new ArrayList<>(Arrays.asList(tags));
    }
    public void validateTagsDoNotContain(String... tagsToCheck) throws IllegalArgumentException {
        if (tagsToCheck == null) {
            throw new IllegalArgumentException("标签数组不能为null");
        }
        for (String tag : tagsToCheck) {
            if (productTags.contains(tag)) {
                throw new IllegalArgumentException("商品的标签列表不应包含标签: " + tag);
            }
        }
    }
    public static void main(String[] args) {
        ProductTagValidator validator = new ProductTagValidator("电子", "书籍", "家具");
        try {
            validator.validateTagsDoNotContain("电子", "食品");
            System.out.println("验证通过，商品标签列表不包含指定的标签。");
        } catch (IllegalArgumentException e) {
            System.out.println(e.getMessage());
        }
    }
}

请设计一个Java方法，该方法用于验证一个商品对象中的标签列表是否不包含指定的一组标签。如果商品的标签列表包含了这些指定的标签之一，方法应该抛出一个异常。
请用Java实现不包含Main函数的完整代码，并遵循如下类型定义：

```java
import java.util.List;
import java.util.Arrays;
import java.util.ArrayList;
public class ProductTagValidator {
    private List<String> productTags;
    public ProductTagValidator(String... tags) {}
    public void validateTagsDoNotContain(String... tagsToCheck) throws IllegalArgumentException {}
}
```

import org.junit.Test;
import org.junit.Before;
import static org.junit.Assert.*;
import java.util.IllegalFormatException;
public class ProductTagValidatorTest {
    private ProductTagValidator validator;
    @Before
    public void setUp() {
        validator = new ProductTagValidator("电子", "书籍", "家具");
    }
    @Test(expected = IllegalArgumentException.class)
    public void testTagsDoNotContain_throwsException_whenTagIsContained() {
        validator.validateTagsDoNotContain("电子", "食品");
    }
    @Test
    public void testTagsDoNotContain_noException_whenTagsAreNotContained() {
        validator.validateTagsDoNotContain("食品", "玩具");
    }
    @Test(expected = IllegalArgumentException.class)
    public void testTagsDoNotContain_throwsException_whenOneTagIsContained() {
        validator.validateTagsDoNotContain("书籍");
    }
    @Test(expected = IllegalArgumentException.class)
    public void testTagsDoNotContain_throwsException_whenTagsToCheckIsNull() {
        validator.validateTagsDoNotContain((String[]) null);
    }
    @Test
    public void testTagsDoNotContain_noException_whenEmptyTagsToCheck() {
        validator.validateTagsDoNotContain();
    }
}


import java.io.BufferedReader;
import java.io.FileReader;
import java.io.IOException;
public class FileToStringConverter {
    public static String fileContentToString(String filePath) throws IOException {
        StringBuilder contentBuilder = new StringBuilder();
        try (BufferedReader br = new BufferedReader(new FileReader(filePath))) {
            String currentLine;
            while ((currentLine = br.readLine()) != null) {
                contentBuilder.append(currentLine).append("\n");
            }
        }
        return contentBuilder.toString();
    }
    public static void main(String[] args) {
        try {
            String filePath = "example.txt";
            String content = fileContentToString(filePath);
            System.out.println(content);
        } catch (IOException e) {
            e.printStackTrace();
        }
    }
}

请编写一个Java方法，该方法能够将文本文件的内容转换为字符串。请确保你的方法能够处理大文件，并且在读取文件时应该考虑到性能优化。此外，如果文件不存在或无法读取，你的方法应该抛出一个适当的异常。请遵循以下指导原则来实现你的解决方案：

- 请使用必要的Java包。
- 保证代码片段是完全独立的，并且清晰易懂。
- 尽量避免与给定代码片段相似的实现。
请用Java实现不包含Main函数的完整代码，并遵循如下类型定义：

```java
import java.io.BufferedReader;
import java.io.FileReader;
import java.io.IOException;
public class FileToStringConverter {
    public static String fileContentToString(String filePath) throws IOException {
    }
}
```

import org.junit.jupiter.api.Test;
import static org.junit.jupiter.api.Assertions.assertEquals;
import static org.junit.jupiter.api.Assertions.assertThrows;
import java.io.IOException;
import java.nio.file.Files;
import java.nio.file.Path;
public class FileToStringConverterTest {
    @Test
    public void testFileContentToString_validFile() throws IOException {
        Path tempFile = Files.createTempFile("testFile", ".txt");
        Files.write(tempFile, "line1\nline2\nline3".getBytes());
        String result = FileToStringConverter.fileContentToString(tempFile.toString());
        assertEquals("line1\nline2\nline3\n", result);
        Files.delete(tempFile);
    }
    @Test
    public void testFileContentToString_emptyFile() throws IOException {
        Path tempFile = Files.createTempFile("emptyFile", ".txt");
        String result = FileToStringConverter.fileContentToString(tempFile.toString());
        assertEquals("", result);
        Files.delete(tempFile);
    }
    @Test
    public void testFileContentToString_invalidFile() {
        assertThrows(IOException.class, () -> {
            FileToStringConverter.fileContentToString("non_existent_file.txt");
        });
    }
    @Test
    public void testFileContentToString_singleLineFile() throws IOException {
        Path tempFile = Files.createTempFile("singleLineFile", ".txt");
        Files.write(tempFile, "singleLine".getBytes());
        String result = FileToStringConverter.fileContentToString(tempFile.toString());
        assertEquals("singleLine\n", result);
        Files.delete(tempFile);
    }
    @Test
    public void testFileContentToString_fileWithNewLines() throws IOException {
        Path tempFile = Files.createTempFile("newLineFile", ".txt");
        Files.write(tempFile, "line1\n\nline2\n".getBytes());
        String result = FileToStringConverter.fileContentToString(tempFile.toString());
        assertEquals("line1\n\nline2\n", result);
        Files.delete(tempFile);
    }
}


import java.lang.System;
class Book {
    private String name;
    private String author;
    public void setBookInfo(String name, String author) {
        this.name = name;
        this.author = author;
    }
    public String getName() {
        return name;
    }
    public String getAuthor() {
        return author;
    }
}
public class BookManager {
    public void testSetBookInfo() {
        System.out.println("测试设置图书信息");
        Book book = new Book();
        book.setBookInfo("Java编程思想", "Bruce Eckel");
        System.out.println("书名: " + book.getName() + ", 作者: " + book.getAuthor());
    }
    public static void main(String[] args) {
        new BookManager().testSetBookInfo();
    }
}

请设计一个Java程序，用于管理图书信息。具体要求如下：

- 需要有一个`Book`类，包含书名（`name`）和作者（`author`）两个属性。
- 在`Book`类中，实现一个方法`setBookInfo`，该方法接收两个字符串参数，分别用于设置书名和作者。
- 此外，需要有一个`BookManager`类，其中包含一个方法`testSetBookInfo`，用于测试`Book`类的`setBookInfo`方法是否能正确设置书名和作者。
- `testSetBookInfo`方法应打印出设置后的书名和作者，以验证设置是否成功。
- 请确保代码完整、清晰，并且所有必要的包都已经导入。
请用Java实现不包含Main函数的完整代码，并遵循如下类型定义：

```java
import java.lang.System;
class Book {
    private String name;
    private String author;
    public void setBookInfo(String name, String author) {
    }
    public String getName() {
        return null;
    }
    public String getAuthor() {
        return null;
    }
}
public class BookManager {
}
```

import static org.junit.jupiter.api.Assertions.assertEquals;
import org.junit.jupiter.api.Test;
class BookTest {
    @Test
    void testSetBookInfoAndGetters() {
        Book book = new Book();
        book.setBookInfo("Java编程思想", "Bruce Eckel");
        assertEquals("Java编程思想", book.getName());
        assertEquals("Bruce Eckel", book.getAuthor());
    }
    @Test
    void testSetBookInfoWithEmptyName() {
        Book book = new Book();
        book.setBookInfo("", "Bruce Eckel");
        assertEquals("", book.getName());
        assertEquals("Bruce Eckel", book.getAuthor());
    }
    @Test
    void testSetBookInfoWithEmptyAuthor() {
        Book book = new Book();
        book.setBookInfo("Java编程思想", "");
        assertEquals("Java编程思想", book.getName());
        assertEquals("", book.getAuthor());
    }
    @Test
    void testSetBookInfoWithNullName() {
        Book book = new Book();
        book.setBookInfo(null, "Bruce Eckel");
        assertEquals(null, book.getName());
        assertEquals("Bruce Eckel", book.getAuthor());
    }
    @Test
    void testSetBookInfoWithNullAuthor() {
        Book book = new Book();
        book.setBookInfo("Java编程思想", null);
        assertEquals("Java编程思想", book.getName());
        assertEquals(null, book.getAuthor());
    }
}


import java.util.Arrays;
public class ArrayAverageCalculator {
    public static double calculateAverage(int[] numbers) {
        if (numbers == null || numbers.length == 0) {
            return 0;
        }
        return Arrays.stream(numbers).average().orElse(0);
    }
    public static void check() {
        int[] testData1 = {1, 2, 3, 4, 5};
        int[] testData2 = {};
        int[] testData3 = {10, 20, 30, 40, 50};
        System.out.println("平均值 (应为3): " + calculateAverage(testData1));
        System.out.println("平均值 (应为0): " + calculateAverage(testData2));
        System.out.println("平均值 (应为30): " + calculateAverage(testData3));
    }
    public static void main(String[] args) {
        check();
    }
}

请编写一个Java方法，用于计算并返回一个数组中所有元素的平均值。该方法应接收一个整型数组作为参数，并返回计算得到的平均值。如果数组为空，应返回0。
请用Java实现不包含Main函数的完整代码，并遵循如下类型定义：

```java
import java.util.Arrays;
public class ArrayAverageCalculator {
    public static double calculateAverage(int[] numbers) {
    }
    public static void check() {
    }
}
```

import org.junit.Assert;
import org.junit.Test;
public class ArrayAverageCalculatorTest {
    @Test
    public void testCalculateAverageWithPositiveNumbers() {
        int[] numbers = {1, 2, 3, 4, 5};
        double expected = 3.0;
        double actual = ArrayAverageCalculator.calculateAverage(numbers);
        Assert.assertEquals(expected, actual, 0.0001);
    }
    @Test
    public void testCalculateAverageWithEmptyArray() {
        int[] numbers = {};
        double expected = 0.0;
        double actual = ArrayAverageCalculator.calculateAverage(numbers);
        Assert.assertEquals(expected, actual, 0.0001);
    }
    @Test
    public void testCalculateAverageWithNullArray() {
        int[] numbers = null;
        double expected = 0.0;
        double actual = ArrayAverageCalculator.calculateAverage(numbers);
        Assert.assertEquals(expected, actual, 0.0001);
    }
    @Test
    public void testCalculateAverageWithAnotherSetOfPositiveNumbers() {
        int[] numbers = {10, 20, 30, 40, 50};
        double expected = 30.0;
        double actual = ArrayAverageCalculator.calculateAverage(numbers);
        Assert.assertEquals(expected, actual, 0.0001);
    }
    @Test
    public void testCalculateAverageWithSingleElement() {
        int[] numbers = {7};
        double expected = 7.0;
        double actual = ArrayAverageCalculator.calculateAverage(numbers);
        Assert.assertEquals(expected, actual, 0.0001);
    }
}


import java.util.ArrayList;
import java.util.List;
public class BookManager {
    static class Book {
        String title;
        String author;
        public Book(String title, String author) {
            this.title = title;
            this.author = author;
        }
    }
    private List<Book> books;
    public BookManager() {
        this.books = new ArrayList<>();
    }
    public void addBook(String title, String author) {
        books.add(new Book(title, author));
    }
    public String findAuthorByTitle(String title) {
        for (Book book : books) {
            if (book.title.equals(title)) {
                return book.author;
            }
        }
        return "书籍不存在";
    }
    public static void main(String[] args) {
        BookManager manager = new BookManager();
        manager.addBook("Java编程思想", "Bruce Eckel");
        manager.addBook("Effective Java", "Joshua Bloch");
        System.out.println(manager.findAuthorByTitle("Java编程思想"));
        System.out.println(manager.findAuthorByTitle("未知书籍"));
    }
}

请编写一个Java程序，用于管理一个图书馆的书籍信息。具体要求如下：

- 需要有一个方法来添加书籍信息到一个列表中。每本书的信息包括书名和作者名。
- 另外一个方法需要能够根据书名搜索并返回该书的作者名。如果书不存在，则返回一个特定的消息，比如“书籍不存在”。
请用Java实现不包含Main函数的完整代码，并遵循如下类型定义：

```java
import java.util.ArrayList;
import java.util.List;
public class BookManager {
    static class Book {
        String title;
        String author;
        public Book(String title, String author) {
        }
    }
    private List<Book> books;
    public BookManager() {
    }
    public void addBook(String title, String author) {
    }
    public String findAuthorByTitle(String title) {
    }
}
```

import org.junit.jupiter.api.BeforeEach;
import org.junit.jupiter.api.Test;
import static org.junit.jupiter.api.Assertions.*;
public class BookManagerTest {
    private BookManager manager;
    @BeforeEach
    public void setUp() {
        manager = new BookManager();
    }
    @Test
    public void testAddBook() {
        manager.addBook("Java编程思想", "Bruce Eckel");
        assertEquals("Bruce Eckel", manager.findAuthorByTitle("Java编程思想"));
    }
    @Test
    public void testFindAuthorByTitle_ExistingBook() {
        manager.addBook("Java编程思想", "Bruce Eckel");
        String author = manager.findAuthorByTitle("Java编程思想");
        assertEquals("Bruce Eckel", author);
    }
    @Test
    public void testFindAuthorByTitle_NonExistingBook() {
        manager.addBook("Java编程思想", "Bruce Eckel");
        String author = manager.findAuthorByTitle("未知书籍");
        assertEquals("书籍不存在", author);
    }
    @Test
    public void testAddMultipleBooks() {
        manager.addBook("Java编程思想", "Bruce Eckel");
        manager.addBook("Effective Java", "Joshua Bloch");
        assertEquals("Joshua Bloch", manager.findAuthorByTitle("Effective Java"));
    }
    @Test
    public void testFindAuthorByTitle_CaseSensitive() {
        manager.addBook("Java编程思想", "Bruce Eckel");
        String author = manager.findAuthorByTitle("java编程思想");
        assertEquals("书籍不存在", author);
    }
}


import java.util.ArrayList;
import java.util.List;
public class BookManager {
    private List<Book> books = new ArrayList<>();
    public String addBook(String title, String author, String isbn, int year) {
        Book newBook = new Book(title, author, isbn, year);
        books.add(newBook);
        return "Book added successfully!";
    }
    public static void main(String[] args) {
        BookManager manager = new BookManager();
        String result = manager.addBook("Java Programming", "John Doe", "123456789", 2020);
        System.out.println(result);
    }
    private static class Book {
        String title;
        String author;
        String isbn;
        int year;
        public Book(String title, String author, String isbn, int year) {
            this.title = title;
            this.author = author;
            this.isbn = isbn;
            this.year = year;
        }
    }
}

请编写一个Java方法，该方法用于在一个简单的图书管理系统中添加新的图书信息。该方法接收图书的标题、作者、ISBN号和出版年份作为参数，并将这些信息保存到系统中。请确保你的代码能够处理添加图书的基本逻辑，并且能够返回一个表示图书已成功添加的消息。

请遵循以下指导原则来完成这个任务：

- 问题描述应尽可能简短且流畅。
- 代码片段应完全自包含且清晰。
- 代码开头必须导入所有使用的包。
- 请尽量使代码片段与给定的代码片段不同（包括类名、函数名、文档字符串和变量名）。
- 问题和解决方案应该用中文书写（代码实现不得使用中文，代码注释应该用英文）。
请用Java实现不包含Main函数的完整代码，并遵循如下类型定义：

```java
import java.util.ArrayList;
import java.util.List;
public class BookManager {
    private List<Book> books = new ArrayList<>();
    public String addBook(String title, String author, String isbn, int year) {
    }
    private static class Book {
        String title;
        String author;
        String isbn;
        int year;
        public Book(String title, String author, String isbn, int year) {
        }
    }
}
```

import org.junit.jupiter.api.Test;
import static org.junit.jupiter.api.Assertions.*;
import java.util.ArrayList;
import java.util.List;
public class BookManagerTest {
    @Test
    public void testAddBook_ValidDetails_ReturnsSuccessMessage() {
        BookManager manager = new BookManager();
        String result = manager.addBook("Effective Java", "Joshua Bloch", "9780134685991", 2018);
        assertEquals("Book added successfully!", result);
    }
    @Test
    public void testAddBook_TitleIsEmpty_ReturnsSuccessMessage() {
        BookManager manager = new BookManager();
        String result = manager.addBook("", "Unknown Author", "0000000000", 2021);
        assertEquals("Book added successfully!", result);
    }
    @Test
    public void testAddBook_AuthorNameIsEmpty_ReturnsSuccessMessage() {
        BookManager manager = new BookManager();
        String result = manager.addBook("Unknown Title", "", "0000000000", 2021);
        assertEquals("Book added successfully!", result);
    }
    @Test
    public void testAddBook_EmptyISBN_ReturnsSuccessMessage() {
        BookManager manager = new BookManager();
        String result = manager.addBook("Some Book", "Some Author", "", 2022);
        assertEquals("Book added successfully!", result);
    }
    @Test
    public void testAddBook_YearZero_ReturnsSuccessMessage() {
        BookManager manager = new BookManager();
        String result = manager.addBook("Ancient Book", "Ancient Author", "1111111111", 0);
        assertEquals("Book added successfully!", result);
    }
    private static class BookManager {
        private List<Book> books = new ArrayList<>();
        public String addBook(String title, String author, String isbn, int year) {
            Book newBook = new Book(title, author, isbn, year);
            books.add(newBook);
            return "Book added successfully!";
        }
    }
    private static class Book {
        String title;
        String author;
        String isbn;
        int year;
        public Book(String title, String author, String isbn, int year) {
            this.title = title;
            this.author = author;
            this.isbn = isbn;
            this.year = year;
        }
    }
}


import java.util.HashMap;
import java.util.Map;
public class BookFinder {
    private Map<Integer, String> books;
    public BookFinder() {
        books = new HashMap<>();
        books.put(1, "Java编程思想");
        books.put(2, "Effective Java");
        books.put(3, "深入理解Java虚拟机");
    }
    public String findBookNameById(int bookId) {
        return books.getOrDefault(bookId, "未找到");
    }
    public static void main(String[] args) {
        BookFinder finder = new BookFinder();
        check(finder.findBookNameById(1), "Java编程思想");
        check(finder.findBookNameById(4), "未找到");
    }
    private static void check(String actual, String expected) {
        if (actual.equals(expected)) {
            System.out.println("测试通过");
        } else {
            System.out.println("测试失败");
        }
    }
}

请编写一个Java程序，实现一个简单的图书管理系统中的图书查找功能。在这个系统中，每本图书都有一个唯一的ID和书名。你需要完成一个方法，通过图书的ID来查找图书的名称。如果找到了对应ID的图书，则返回该图书的名称；如果没有找到，则返回一个特定的字符串表示未找到。
请用Java实现不包含Main函数的完整代码，并遵循如下类型定义：

```java
import java.util.HashMap;
import java.util.Map;
public class BookFinder {
    private Map<Integer, String> books;
    public BookFinder() {
    }
    public String findBookNameById(int bookId) {
    }
}
```

import org.junit.jupiter.api.Assertions;
import org.junit.jupiter.api.Test;
public class BookFinderTest {
    @Test
    public void testFindBookNameById_bookExists() {
        BookFinder finder = new BookFinder();
        Assertions.assertEquals("Java编程思想", finder.findBookNameById(1));
    }
    @Test
    public void testFindBookNameById_bookExists2() {
        BookFinder finder = new BookFinder();
        Assertions.assertEquals("Effective Java", finder.findBookNameById(2));
    }
    @Test
    public void testFindBookNameById_bookExists3() {
        BookFinder finder = new BookFinder();
        Assertions.assertEquals("深入理解Java虚拟机", finder.findBookNameById(3));
    }
    @Test
    public void testFindBookNameById_bookNotExists() {
        BookFinder finder = new BookFinder();
        Assertions.assertEquals("未找到", finder.findBookNameById(4));
    }
    @Test
    public void testFindBookNameById_bookNotExistsNegative() {
        BookFinder finder = new BookFinder();
        Assertions.assertEquals("未找到", finder.findBookNameById(-1));
    }
}


import java.util.logging.Logger;
public class DatabaseErrorChecker {
    private static final Logger logger = Logger.getLogger(DatabaseErrorChecker.class.getName());
    public static void checkDbError(String operation, int errorCode) {
        if (errorCode != 0) {
            String errorMessage = operation + ": DbError " + errorCode;
            logger.severe(errorMessage);
            throw new DatabaseOperationException(errorMessage);
        }
    }
    public static void main(String[] args) {
        try {
            checkDbError("UpdateUser", 1001);
        } catch (DatabaseOperationException e) {
            System.out.println("Caught exception: " + e.getMessage());
        }
    }
}
class DatabaseOperationException extends RuntimeException {
    public DatabaseOperationException(String message) {
        super(message);
    }
}

请编写一个Java方法，用于检查数据库操作中是否存在错误，并记录错误信息。如果发现错误，该方法应该抛出一个异常，异常信息中包含操作名称和具体的错误代码。
请用Java实现不包含Main函数的完整代码，并遵循如下类型定义：

```java
import java.util.logging.Logger;
public class DatabaseErrorChecker {
    private static final Logger logger = Logger.getLogger(DatabaseErrorChecker.class.getName());
    public static void checkDbError(String operation, int errorCode) {
    }
}
class DatabaseOperationException extends RuntimeException {
    public DatabaseOperationException(String message) {
    }
}
```

import org.junit.jupiter.api.Test;
import static org.junit.jupiter.api.Assertions.*;
public class DatabaseErrorCheckerTest {
    @Test
    public void testCheckDbErrorWithNoError() {
        assertDoesNotThrow(() -> DatabaseErrorChecker.checkDbError("SelectUser", 0));
    }
    @Test
    public void testCheckDbErrorWithError() {
        DatabaseOperationException exception = assertThrows(DatabaseOperationException.class, () -> {
            DatabaseErrorChecker.checkDbError("UpdateUser", 1001);
        });
        assertEquals("UpdateUser: DbError 1001", exception.getMessage());
    }
    @Test
    public void testCheckDbErrorAnotherOperationWithError() {
        DatabaseOperationException exception = assertThrows(DatabaseOperationException.class, () -> {
            DatabaseErrorChecker.checkDbError("DeleteUser", 1002);
        });
        assertEquals("DeleteUser: DbError 1002", exception.getMessage());
    }
    @Test
    public void testCheckDbErrorWithZeroErrorCode() {
        assertDoesNotThrow(() -> DatabaseErrorChecker.checkDbError("InsertUser", 0));
    }
    @Test
    public void testCheckDbErrorWithNegativeErrorCode() {
        DatabaseOperationException exception = assertThrows(DatabaseOperationException.class, () -> {
            DatabaseErrorChecker.checkDbError("FetchUser", -1);
        });
        assertEquals("FetchUser: DbError -1", exception.getMessage());
    }
}


import java.util.Arrays;
public class CoordinateMapper {
    public static long[] map3DPoint(double longitude, double minLongitude, double maxLongitude,
                                    double latitude, double minLatitude, double maxLatitude,
                                    double timestamp, double minTimestamp, double maxTimestamp,
                                    long maxValue) {
        long x = mapValue(longitude, minLongitude, maxLongitude, maxValue);
        long y = mapValue(latitude, minLatitude, maxLatitude, maxValue);
        long z = mapValue(timestamp, minTimestamp, maxTimestamp, maxValue);
        return new long[]{x, y, z};
    }
    private static long mapValue(double value, double minValue, double maxValue, long targetMaxValue) {
        return Math.round((value - minValue) / (maxValue - minValue) * targetMaxValue);
    }
    public static void main(String[] args) {
        double longitude = 116.4074, minLongitude = 116.0, maxLongitude = 117.0;
        double latitude = 39.9042, minLatitude = 39.0, maxLatitude = 40.0;
        double timestamp = 1588000000, minTimestamp = 1587000000, maxTimestamp = 1589000000;
        long maxValue = 1000;
        long[] mappedCoordinates = map3DPoint(longitude, minLongitude, maxLongitude, latitude, minLatitude, maxLatitude, timestamp, minTimestamp, maxTimestamp, maxValue);
        System.out.println("映射后的坐标: " + Arrays.toString(mappedCoordinates));
    }
}

请编写一个Java方法，用于将一个三维点的坐标（经度、纬度、时间）映射到一个三维空间的新坐标系中。新坐标系的每个维度的最大值由用户指定。具体来说，你需要根据给定的经度、纬度和时间的最小值和最大值，将原始的三维点映射到一个以0为最小值、用户指定的最大值为最大值的新坐标系中。请确保你的方法能够处理各种输入，并返回一个包含映射后的x、y、z坐标的长整型数组。
请用Java实现不包含Main函数的完整代码，并遵循如下类型定义：

```java
import java.util.Arrays;
public class CoordinateMapper {
    public static long[] map3DPoint(double longitude, double minLongitude, double maxLongitude,
                                    double latitude, double minLatitude, double maxLatitude,
                                    double timestamp, double minTimestamp, double maxTimestamp,
                                    long maxValue) {
    }
    private static long mapValue(double value, double minValue, double maxValue, long targetMaxValue) {
    }
}
```

import org.junit.jupiter.api.Test;
import static org.junit.jupiter.api.Assertions.*;
public class CoordinateMapperTest {
    @Test
    public void testMap3DPoint_withinBounds() {
        double longitude = 116.4074, minLongitude = 116.0, maxLongitude = 117.0;
        double latitude = 39.9042, minLatitude = 39.0, maxLatitude = 40.0;
        double timestamp = 1588000000, minTimestamp = 1587000000, maxTimestamp = 1589000000;
        long maxValue = 1000;
        long[] result = CoordinateMapper.map3DPoint(longitude, minLongitude, maxLongitude,
                                                     latitude, minLatitude, maxLatitude,
                                                     timestamp, minTimestamp, maxTimestamp,
                                                     maxValue);
        assertArrayEquals(new long[]{407, 904, 500}, result);
    }
    @Test
    public void testMap3DPoint_edgeValues() {
        double longitude = 116.0, minLongitude = 116.0, maxLongitude = 117.0;
        double latitude = 40.0, minLatitude = 39.0, maxLatitude = 40.0;
        double timestamp = 1587000000, minTimestamp = 1587000000, maxTimestamp = 1589000000;
        long maxValue = 1000;
        long[] result = CoordinateMapper.map3DPoint(longitude, minLongitude, maxLongitude,
                                                     latitude, minLatitude, maxLatitude,
                                                     timestamp, minTimestamp, maxTimestamp,
                                                     maxValue);
        assertArrayEquals(new long[]{0, 1000, 0}, result);
    }
    @Test
    public void testMap3DPoint_midRangeValues() {
        double longitude = 116.5, minLongitude = 116.0, maxLongitude = 117.0;
        double latitude = 39.5, minLatitude = 39.0, maxLatitude = 40.0;
        double timestamp = 1588000000, minTimestamp = 1587000000, maxTimestamp = 1589000000;
        long maxValue = 1000;
        long[] result = CoordinateMapper.map3DPoint(longitude, minLongitude, maxLongitude,
                                                     latitude, minLatitude, maxLatitude,
                                                     timestamp, minTimestamp, maxTimestamp,
                                                     maxValue);
        assertArrayEquals(new long[]{500, 500, 500}, result);
    }
    @Test
    public void testMap3DPoint_minValues() {
        double longitude = 116.0, minLongitude = 116.0, maxLongitude = 117.0;
        double latitude = 39.0, minLatitude = 39.0, maxLatitude = 40.0;
        double timestamp = 1587000000, minTimestamp = 1587000000, maxTimestamp = 1589000000;
        long maxValue = 1000;
        long[] result = CoordinateMapper.map3DPoint(longitude, minLongitude, maxLongitude,
                                                     latitude, minLatitude, maxLatitude,
                                                     timestamp, minTimestamp, maxTimestamp,
                                                     maxValue);
        assertArrayEquals(new long[]{0, 0, 0}, result);
    }
    @Test
    public void testMap3DPoint_maxValues() {
        double longitude = 117.0, minLongitude = 116.0, maxLongitude = 117.0;
        double latitude = 40.0, minLatitude = 39.0, maxLatitude = 40.0;
        double timestamp = 1589000000, minTimestamp = 1587000000, maxTimestamp = 1589000000;
        long maxValue = 1000;
        long[] result = CoordinateMapper.map3DPoint(longitude, minLongitude, maxLongitude,
                                                     latitude, minLatitude, maxLatitude,
                                                     timestamp, minTimestamp, maxTimestamp,
                                                     maxValue);
        assertArrayEquals(new long[]{1000, 1000, 1000}, result);
    }
}


import java.io.BufferedReader;
import java.io.File;
import java.io.FileReader;
import java.io.IOException;
public class FileContentComparator {
    public static void compareTextFiles(File file1, File file2) {
        try (BufferedReader reader1 = new BufferedReader(new FileReader(file1));
             BufferedReader reader2 = new BufferedReader(new FileReader(file2))) {
            String line1, line2;
            boolean areFilesDifferent = false;
            while ((line1 = reader1.readLine()) != null && (line2 = reader2.readLine()) != null) {
                if (!line1.trim().equals(line2.trim())) {
                    areFilesDifferent = true;
                    break;
                }
            }
            if (line1 != null || reader2.readLine() != null) {
                areFilesDifferent = true;
            }
            if (areFilesDifferent) {
                System.out.println("文件内容不同");
            } else {
                System.out.println("文件内容相同");
            }
        } catch (IOException e) {
            e.printStackTrace();
        }
    }
    public static void main(String[] args) {
        File file1 = new File("path/to/your/firstFile.txt");
        File file2 = new File("path/to/your/secondFile.txt");
        compareTextFiles(file1, file2);
    }
}

请编写一个Java程序，用于比较两个文本文件的内容是否完全相同。如果内容完全相同，程序应输出“文件内容相同”，如果不同，则输出“文件内容不同”。请确保你的程序能够有效处理文本文件，并且在比较文件内容时忽略行尾的空白字符。
请用Java实现不包含Main函数的完整代码，并遵循如下类型定义：

```java
import java.io.BufferedReader;
import java.io.File;
import java.io.FileReader;
import java.io.IOException;
public class FileContentComparator {
    public static void compareTextFiles(File file1, File file2) {
    }
}
```

import org.junit.jupiter.api.Test;
import java.io.File;
import java.io.FileWriter;
import java.io.IOException;
import java.nio.file.Files;
import java.nio.file.Path;
public class FileContentComparatorTest {
    @Test
    public void testCompareTextFiles_SameContent() throws IOException {
        File file1 = createTempFile("line1\nline2\nline3\n");
        File file2 = createTempFile("line1\nline2\nline3\n");
        FileContentComparator.compareTextFiles(file1, file2);
        file1.delete();
        file2.delete();
    }
    @Test
    public void testCompareTextFiles_DifferentContent() throws IOException {
        File file1 = createTempFile("line1\nline2\nline3\n");
        File file2 = createTempFile("line1\nline2\ndifferent line\n");
        FileContentComparator.compareTextFiles(file1, file2);
        file1.delete();
        file2.delete();
    }
    @Test
    public void testCompareTextFiles_OneFileIsEmpty() throws IOException {
        File file1 = createTempFile("");
        File file2 = createTempFile("line1\nline2\nline3\n");
        FileContentComparator.compareTextFiles(file1, file2);
        file1.delete();
        file2.delete();
    }
    @Test
    public void testCompareTextFiles_BothFilesEmpty() throws IOException {
        File file1 = createTempFile("");
        File file2 = createTempFile("");
        FileContentComparator.compareTextFiles(file1, file2);
        file1.delete();
        file2.delete();
    }
    @Test
    public void testCompareTextFiles_FirstFileLonger() throws IOException {
        File file1 = createTempFile("line1\nline2\nline3\nline4\n");
        File file2 = createTempFile("line1\nline2\nline3\n");
        FileContentComparator.compareTextFiles(file1, file2);
        file1.delete();
        file2.delete();
    }
    private File createTempFile(String content) throws IOException {
        Path tempFile = Files.createTempFile("testFile", ".txt");
        FileWriter writer = new FileWriter(tempFile.toFile());
        writer.write(content);
        writer.close();
        return tempFile.toFile();
    }
}


import java.util.ArrayList;
import java.util.List;
import java.util.regex.Pattern;
public class EmailValidator {
    private static final String ERROR_INVALID_EMAIL = "INVALID_EMAIL";
    private List<String> errors = new ArrayList<>();
    public void validateEmail(String email) {
        String emailRegex = "^[a-zA-Z0-9_+&*-]+(?:\\.[a-zA-Z0-9_+&*-]+)*@(?:[a-zA-Z0-9-]+\\.)+[a-zA-Z]{2,7}$";
        if (email == null || !Pattern.matches(emailRegex, email)) {
            errors.add(ERROR_INVALID_EMAIL);
        }
    }
    public List<String> getErrors() {
        return errors;
    }
    public static void main(String[] args) {
        EmailValidator validator = new EmailValidator();
        validator.validateEmail("example@example.com");
        validator.validateEmail("invalid-email");
        validator.validateEmail(null);
        System.out.println("Number of errors: " + validator.getErrors().size());
        for (String error : validator.getErrors()) {
            System.out.println(error);
        }
    }
}

请编写一个Java方法，用于检查传入的字符串是否为有效的电子邮件地址。如果不是，该方法应该将相应的错误信息添加到一个错误列表中。请确保你的代码能够处理null值的情况，并且在检查电子邮件有效性时，考虑到电子邮件地址通常包含用户名、"@"符号以及域名。如果电子邮件地址无效，应该使用特定的错误代码"INVALID_EMAIL"来标记。
请用Java实现不包含Main函数的完整代码，并遵循如下类型定义：

```java
import java.util.ArrayList;
import java.util.List;
import java.util.regex.Pattern;
public class EmailValidator {
    private static final String ERROR_INVALID_EMAIL = "INVALID_EMAIL";
    private List<String> errors = new ArrayList<>();
    public void validateEmail(String email) {
    }
    public List<String> getErrors() {
        return null;
    }
}
```

import static org.junit.Assert.*;
import org.junit.Before;
import org.junit.Test;
import java.util.List;
public class EmailValidatorTest {
    private EmailValidator emailValidator;
    @Before
    public void setUp() {
        emailValidator = new EmailValidator();
    }
    @Test
    public void testValidEmail() {
        emailValidator.validateEmail("example@example.com");
        List<String> errors = emailValidator.getErrors();
        assertTrue(errors.isEmpty());
    }
    @Test
    public void testInvalidEmail() {
        emailValidator.validateEmail("invalid-email");
        List<String> errors = emailValidator.getErrors();
        assertEquals(1, errors.size());
        assertEquals("INVALID_EMAIL", errors.get(0));
    }
    @Test
    public void testNullEmail() {
        emailValidator.validateEmail(null);
        List<String> errors = emailValidator.getErrors();
        assertEquals(1, errors.size());
        assertEquals("INVALID_EMAIL", errors.get(0));
    }
    @Test
    public void testMultipleEmails() {
        emailValidator.validateEmail("example@example.com");
        emailValidator.validateEmail("another@example.com");
        List<String> errors = emailValidator.getErrors();
        assertTrue(errors.isEmpty());
    }
    @Test
    public void testMultipleInvalidEmails() {
        emailValidator.validateEmail("example@example.com");
        emailValidator.validateEmail("invalid-email");
        emailValidator.validateEmail(null);
        List<String> errors = emailValidator.getErrors();
        assertEquals(2, errors.size());
        assertEquals("INVALID_EMAIL", errors.get(0));
        assertEquals("INVALID_EMAIL", errors.get(1));
    }
}


import java.awt.Color;
public class ColorParser {
    public static Color parseColor(String colorStr, Color defaultColor) {
        try {
            String[] parts = colorStr.split(",");
            if (parts.length != 3) {
                return defaultColor;
            }
            int r = Integer.parseInt(parts[0]);
            int g = Integer.parseInt(parts[1]);
            int b = Integer.parseInt(parts[2]);
            if (r < 0 || r > 255 || g < 0 || g > 255 || b < 0 || b > 255) {
                return defaultColor;
            }
            return new Color(r, g, b);
        } catch (NumberFormatException e) {
            return defaultColor;
        }
    }
    public static void main(String[] args) {
        System.out.println(parseColor("255,0,0", Color.BLACK).equals(Color.RED));
        System.out.println(parseColor("255,0", Color.BLACK).equals(Color.BLACK));
        System.out.println(parseColor("256,0,0", Color.BLACK).equals(Color.BLACK));
    }
}

请编写一个Java方法，用于解析一个特定格式的字符串，并根据这个字符串创建一个`Color`对象。字符串格式为"R,G,B"，其中R、G、B分别代表红色、绿色和蓝色的值，这些值的范围是0到255。如果字符串格式不正确或RGB值不在有效范围内，方法应返回一个默认的颜色对象。
请用Java实现不包含Main函数的完整代码，并遵循如下类型定义：

```java
import java.awt.Color;
public class ColorParser {
    public static Color parseColor(String colorStr, Color defaultColor) {
    }
}
```

import java.awt.Color;
import org.junit.Test;
import static org.junit.Assert.*;
public class ColorParserTest {
    @Test
    public void testValidColorString() {
        Color actual = ColorParser.parseColor("255,0,0", Color.BLACK);
        assertEquals(new Color(255, 0, 0), actual);
    }
    @Test
    public void testInvalidFormatString() {
        Color actual = ColorParser.parseColor("255,0", Color.BLACK);
        assertEquals(Color.BLACK, actual);
    }
    @Test
    public void testValueOutOfRange() {
        Color actual = ColorParser.parseColor("256,0,0", Color.BLACK);
        assertEquals(Color.BLACK, actual);
    }
    @Test
    public void testNegativeValue() {
        Color actual = ColorParser.parseColor("255,-1,0", Color.BLACK);
        assertEquals(Color.BLACK, actual);
    }
    @Test
    public void testNonNumericValues() {
        Color actual = ColorParser.parseColor("255,abc,0", Color.BLACK);
        assertEquals(Color.BLACK, actual);
    }
}


import java.util.ArrayList;
import java.util.Arrays;
public class UpperCaseConverter {
    public static ArrayList<String> convertToUpper(ArrayList<String> strings) {
        ArrayList<String> upperCaseStrings = new ArrayList<>();
        for (String str : strings) {
            upperCaseStrings.add(str.toUpperCase());
        }
        return upperCaseStrings;
    }
    public static void main(String[] args) {
        ArrayList<String> testStrings = new ArrayList<>(Arrays.asList("hello", "world", "java"));
        ArrayList<String> upperCaseStrings = convertToUpper(testStrings);
        System.out.println(upperCaseStrings);
        ArrayList<String> emptyList = new ArrayList<>();
        ArrayList<String> resultForEmptyList = convertToUpper(emptyList);
        System.out.println(resultForEmptyList);
    }
}

请编写一个Java方法，该方法用于处理字符串数组，将数组中的每个字符串转换为大写，并将这些大写字符串添加到一个新的ArrayList中。请确保你的方法能够处理空数组的情况，并且在方法的末尾返回这个新的ArrayList。请遵循以下指导原则来完成这个任务：

- 方法应该是公开的和静态的。
- 方法的参数应该是一个字符串数组。
- 方法的返回类型应该是ArrayList<String>。
- 请确保代码片段是完全独立的，并且在代码开始处导入了所有必要的包。
请用Java实现不包含Main函数的完整代码，并遵循如下类型定义：

```java
import java.util.ArrayList;
import java.util.Arrays;
public class UpperCaseConverter {
    public static ArrayList<String> convertToUpper(ArrayList<String> strings) {
    }
}
```

import org.junit.jupiter.api.Test;
import static org.junit.jupiter.api.Assertions.assertEquals;
import java.util.ArrayList;
import java.util.Arrays;
public class UpperCaseConverterTest {
    @Test
    public void testConvertToUpper_withNormalStrings() {
        ArrayList<String> input = new ArrayList<>(Arrays.asList("hello", "world", "java"));
        ArrayList<String> expected = new ArrayList<>(Arrays.asList("HELLO", "WORLD", "JAVA"));
        assertEquals(expected, UpperCaseConverter.convertToUpper(input));
    }
    @Test
    public void testConvertToUpper_withEmptyList() {
        ArrayList<String> input = new ArrayList<>();
        ArrayList<String> expected = new ArrayList<>();
        assertEquals(expected, UpperCaseConverter.convertToUpper(input));
    }
    @Test
    public void testConvertToUpper_withMixCaseStrings() {
        ArrayList<String> input = new ArrayList<>(Arrays.asList("HelLo", "WOrLd", "JaVA"));
        ArrayList<String> expected = new ArrayList<>(Arrays.asList("HELLO", "WORLD", "JAVA"));
        assertEquals(expected, UpperCaseConverter.convertToUpper(input));
    }
    @Test
    public void testConvertToUpper_withAllUpperCaseStrings() {
        ArrayList<String> input = new ArrayList<>(Arrays.asList("HELLO", "WORLD", "JAVA"));
        ArrayList<String> expected = new ArrayList<>(Arrays.asList("HELLO", "WORLD", "JAVA"));
        assertEquals(expected, UpperCaseConverter.convertToUpper(input));
    }
    @Test
    public void testConvertToUpper_singleElementList() {
        ArrayList<String> input = new ArrayList<>(Arrays.asList("single"));
        ArrayList<String> expected = new ArrayList<>(Arrays.asList("SINGLE"));
        assertEquals(expected, UpperCaseConverter.convertToUpper(input));
    }
}


import java.math.BigDecimal;
public class ShoppingCartCalculator {
    public static BigDecimal calculateTotalPrice(BigDecimal unitPrice, int quantity) {
        return unitPrice.multiply(new BigDecimal(quantity));
    }
    public static void main(String[] args) {
        BigDecimal unitPrice = new BigDecimal("29.99");
        int quantity = 3;
        BigDecimal expectedTotalPrice = new BigDecimal("89.97");
        BigDecimal totalPrice = calculateTotalPrice(unitPrice, quantity);
        if (totalPrice.compareTo(expectedTotalPrice) == 0) {
            System.out.println("计算结果正确: " + totalPrice);
        } else {
            System.out.println("计算结果错误: " + totalPrice);
        }
    }
}

请设计一个简单的Java函数，该函数用于处理购物车中商品的价格计算。给定一个商品的单价和数量，计算并返回该商品的总价。
请用Java实现不包含Main函数的完整代码，并遵循如下类型定义：

```java
import java.math.BigDecimal;
public class ShoppingCartCalculator {
    public static BigDecimal calculateTotalPrice(BigDecimal unitPrice, int quantity) {
    }
}
```

import org.junit.jupiter.api.Test;
import java.math.BigDecimal;
import static org.junit.jupiter.api.Assertions.assertEquals;
public class ShoppingCartCalculatorTest {
    @Test
    public void testCalculateTotalPrice_withPositiveQuantity() {
        BigDecimal unitPrice = new BigDecimal("29.99");
        int quantity = 3;
        BigDecimal expectedTotalPrice = new BigDecimal("89.97");
        BigDecimal totalPrice = ShoppingCartCalculator.calculateTotalPrice(unitPrice, quantity);
        assertEquals(0, totalPrice.compareTo(expectedTotalPrice));
    }
    @Test
    public void testCalculateTotalPrice_withZeroQuantity() {
        BigDecimal unitPrice = new BigDecimal("29.99");
        int quantity = 0;
        BigDecimal expectedTotalPrice = new BigDecimal("0.00");
        BigDecimal totalPrice = ShoppingCartCalculator.calculateTotalPrice(unitPrice, quantity);
        assertEquals(0, totalPrice.compareTo(expectedTotalPrice));
    }
    @Test
    public void testCalculateTotalPrice_withNegativeQuantity() {
        BigDecimal unitPrice = new BigDecimal("29.99");
        int quantity = -3;
        BigDecimal expectedTotalPrice = new BigDecimal("-89.97");
        BigDecimal totalPrice = ShoppingCartCalculator.calculateTotalPrice(unitPrice, quantity);
        assertEquals(0, totalPrice.compareTo(expectedTotalPrice));
    }
    @Test
    public void testCalculateTotalPrice_withHighPrecisionUnitPrice() {
        BigDecimal unitPrice = new BigDecimal("29.99999");
        int quantity = 3;
        BigDecimal expectedTotalPrice = new BigDecimal("89.99997");
        BigDecimal totalPrice = ShoppingCartCalculator.calculateTotalPrice(unitPrice, quantity);
        assertEquals(0, totalPrice.compareTo(expectedTotalPrice));
    }
    @Test
    public void testCalculateTotalPrice_withZeroUnitPrice() {
        BigDecimal unitPrice = new BigDecimal("0.00");
        int quantity = 3;
        BigDecimal expectedTotalPrice = new BigDecimal("0.00");
        BigDecimal totalPrice = ShoppingCartCalculator.calculateTotalPrice(unitPrice, quantity);
        assertEquals(0, totalPrice.compareTo(expectedTotalPrice));
    }
}


import java.util.Objects;
class Department {
    String name;
    Department(String name) {
        this.name = name;
    }
}
class Position {
    String title;
    Position(String title) {
        this.title = title;
    }
}
class Level {
    String rank;
    Level(String rank) {
        this.rank = rank;
    }
}
class PriceInfo {
    Department department;
    Position position;
    Level level;
    PriceInfo(Department department, Position position, Level level) {
        this.department = department;
        this.position = position;
        this.level = level;
    }
}
class Employee {
    String id;
    PriceInfo domesticPrice;
    PriceInfo internationalPrice;
    Department department;
    Position position;
    Level level;
    Employee(String id, PriceInfo domesticPrice, PriceInfo internationalPrice) {
        this.id = id;
        this.domesticPrice = domesticPrice;
        this.internationalPrice = internationalPrice;
    }
    void updateEmployeeDetails(boolean isDomestic) {
        PriceInfo priceInfo = isDomestic ? this.domesticPrice : this.internationalPrice;
        if (Objects.nonNull(priceInfo)) {
            this.department = priceInfo.department;
            this.position = priceInfo.position;
            this.level = priceInfo.level;
        }
    }
}
public class EmployeeUpdater {
    public static void main(String[] args) {
        Department dept1 = new Department("研发部");
        Position pos1 = new Position("软件工程师");
        Level lev1 = new Level("P2");
        Department dept2 = new Department("市场部");
        Position pos2 = new Position("市场专员");
        Level lev2 = new Level("P1");
        PriceInfo domestic = new PriceInfo(dept1, pos1, lev1);
        PriceInfo international = new PriceInfo(dept2, pos2, lev2);
        Employee emp = new Employee("001", domestic, international);
        emp.updateEmployeeDetails(true);
        System.out.println("更新为国内信息后的部门：" + emp.department.name);
        emp.updateEmployeeDetails(false);
        System.out.println("更新为国际信息后的部门：" + emp.department.name);
    }
}

请编写一个Java方法，用于更新一个员工的详细信息。假设我们有一个`Employee`类，其中包含员工的基本信息和两种类型的价格信息：`domesticPrice`和`internationalPrice`。每种价格信息都包含多个属性，如`department`、`position`、`level`等。根据员工的价格类型（国内或国际），我们需要更新员工的部门、职位、级别等信息。如果员工的价格类型是国内的，我们就使用`domesticPrice`中的信息更新员工信息；如果是国际的，就使用`internationalPrice`中的信息更新。请注意，所有使用的类和方法都应该在代码片段中明确导入和定义。
请用Java实现不包含Main函数的完整代码，并遵循如下类型定义：

```java
import java.util.Objects;
class Department {
    String name;
    Department(String name) {
    }
}
class Position {
    String title;
    Position(String title) {
    }
}
class Level {
    String rank;
    Level(String rank) {
    }
}
class PriceInfo {
    Department department;
    Position position;
    Level level;
    PriceInfo(Department department, Position position, Level level) {
    }
}
class Employee {
    String id;
    PriceInfo domesticPrice;
    PriceInfo internationalPrice;
    Department department;
    Position position;
    Level level;
    Employee(String id, PriceInfo domesticPrice, PriceInfo internationalPrice) {
    }
    void updateEmployeeDetails(boolean isDomestic) {
    }
}
public class EmployeeUpdater {
}
```

import org.junit.jupiter.api.Test;
import static org.junit.jupiter.api.Assertions.*;
class DepartmentTest {
    @Test
    void testDepartmentConstructor() {
        Department dept = new Department("研发部");
        assertEquals("研发部", dept.name);
    }
}
class PositionTest {
    @Test
    void testPositionConstructor() {
        Position pos = new Position("软件工程师");
        assertEquals("软件工程师", pos.title);
    }
}
class LevelTest {
    @Test
    void testLevelConstructor() {
        Level level = new Level("P2");
        assertEquals("P2", level.rank);
    }
}
class PriceInfoTest {
    @Test
    void testPriceInfoConstructor() {
        Department dept = new Department("研发部");
        Position pos = new Position("软件工程师");
        Level level = new Level("P2");
        PriceInfo priceInfo = new PriceInfo(dept, pos, level);
        assertEquals(dept, priceInfo.department);
        assertEquals(pos, priceInfo.position);
        assertEquals(level, priceInfo.level);
    }
}
class EmployeeTest {
    @Test
    void testUpdateEmployeeDetailsDomestic() {
        Department dept1 = new Department("研发部");
        Position pos1 = new Position("软件工程师");
        Level lev1 = new Level("P2");
        Department dept2 = new Department("市场部");
        Position pos2 = new Position("市场专员");
        Level lev2 = new Level("P1");
        PriceInfo domestic = new PriceInfo(dept1, pos1, lev1);
        PriceInfo international = new PriceInfo(dept2, pos2, lev2);
        Employee emp = new Employee("001", domestic, international);
        emp.updateEmployeeDetails(true);
        assertEquals(dept1, emp.department);
        assertEquals(pos1, emp.position);
        assertEquals(lev1, emp.level);
    }
    @Test
    void testUpdateEmployeeDetailsInternational() {
        Department dept1 = new Department("研发部");
        Position pos1 = new Position("软件工程师");
        Level lev1 = new Level("P2");
        Department dept2 = new Department("市场部");
        Position pos2 = new Position("市场专员");
        Level lev2 = new Level("P1");
        PriceInfo domestic = new PriceInfo(dept1, pos1, lev1);
        PriceInfo international = new PriceInfo(dept2, pos2, lev2);
        Employee emp = new Employee("001", domestic, international);
        emp.updateEmployeeDetails(false);
        assertEquals(dept2, emp.department);
        assertEquals(pos2, emp.position);
        assertEquals(lev2, emp.level);
    }
    @Test
    void testUpdateEmployeeDetailsNullPriceInfo() {
        Department dept1 = new Department("研发部");
        Position pos1 = new Position("软件工程师");
        Level lev1 = new Level("P2");
        PriceInfo domestic = new PriceInfo(dept1, pos1, lev1);
        Employee emp = new Employee("001", domestic, null);
        emp.updateEmployeeDetails(false);
        assertNull(emp.department);
        assertNull(emp.position);
        assertNull(emp.level);
    }
}


import java.time.LocalDateTime;
class AuthorizationInfo {
    private String modelId;
    private String accessToken;
    private LocalDateTime expiresOn;
    private String resourceId;
    private String resourceRegion;
    public AuthorizationInfo(String modelId, String accessToken, LocalDateTime expiresOn, String resourceId, String resourceRegion) {
        this.modelId = modelId;
        this.accessToken = accessToken;
        this.expiresOn = expiresOn;
        this.resourceId = resourceId;
        this.resourceRegion = resourceRegion;
    }
    public String getModelId() {
        return modelId;
    }
    public String getAccessToken() {
        return accessToken;
    }
    public LocalDateTime getExpiresOn() {
        return expiresOn;
    }
    public String getResourceId() {
        return resourceId;
    }
    public String getResourceRegion() {
        return resourceRegion;
    }
}
public class AuthorizationGenerator {
    public static void generateAuthorizationInfo() {
        String modelId = "model-123";
        String accessToken = "access-token-abc";
        LocalDateTime expiresOn = LocalDateTime.now().plusDays(30);
        String resourceId = "resource-id-xyz";
        String resourceRegion = "resource-region-789";
        AuthorizationInfo authorizationInfo = new AuthorizationInfo(modelId, accessToken, expiresOn, resourceId, resourceRegion);
        System.out.printf("授权信息：模型ID: %s, 访问令牌: %s, 过期时间: %s, 目标资源ID: %s, 目标资源区域: %s%n",
                authorizationInfo.getModelId(),
                authorizationInfo.getAccessToken(),
                authorizationInfo.getExpiresOn(),
                authorizationInfo.getResourceId(),
                authorizationInfo.getResourceRegion()
        );
    }
    public static void main(String[] args) {
        generateAuthorizationInfo();
    }
}

请编写一个Java方法，该方法能够生成一个授权信息对象，并打印出该对象的详细信息。授权信息包括模型ID、访问令牌、过期时间、目标资源ID和目标资源区域。请确保你的方法包含所有必要的实现细节和包导入。
请用Java实现不包含Main函数的完整代码，并遵循如下类型定义：

```java
import java.time.LocalDateTime;
class AuthorizationInfo {
    private String modelId;
    private String accessToken;
    private LocalDateTime expiresOn;
    private String resourceId;
    private String resourceRegion;
    public AuthorizationInfo(String modelId, String accessToken, LocalDateTime expiresOn, String resourceId, String resourceRegion) {
    }
    public String getModelId() {
    }
    public String getAccessToken() {
    }
    public LocalDateTime getExpiresOn() {
    }
    public String getResourceId() {
    }
    public String getResourceRegion() {
    }
}
public class AuthorizationGenerator {
    public static void generateAuthorizationInfo() {
    }
}
```

import org.junit.jupiter.api.Test;
import static org.junit.jupiter.api.Assertions.*;
import java.time.LocalDateTime;
class AuthorizationInfoTest {
    @Test
    public void testGetModelId() {
        AuthorizationInfo authInfo = new AuthorizationInfo("model-123", "access-token-abc", LocalDateTime.now().plusDays(30), "resource-id-xyz", "resource-region-789");
        assertEquals("model-123", authInfo.getModelId());
    }
    @Test
    public void testGetAccessToken() {
        AuthorizationInfo authInfo = new AuthorizationInfo("model-123", "access-token-abc", LocalDateTime.now().plusDays(30), "resource-id-xyz", "resource-region-789");
        assertEquals("access-token-abc", authInfo.getAccessToken());
    }
    @Test
    public void testGetExpiresOn() {
        LocalDateTime futureDate = LocalDateTime.now().plusDays(30);
        AuthorizationInfo authInfo = new AuthorizationInfo("model-123", "access-token-abc", futureDate, "resource-id-xyz", "resource-region-789");
        assertEquals(futureDate, authInfo.getExpiresOn());
    }
    @Test
    public void testGetResourceId() {
        AuthorizationInfo authInfo = new AuthorizationInfo("model-123", "access-token-abc", LocalDateTime.now().plusDays(30), "resource-id-xyz", "resource-region-789");
        assertEquals("resource-id-xyz", authInfo.getResourceId());
    }
    @Test
    public void testGetResourceRegion() {
        AuthorizationInfo authInfo = new AuthorizationInfo("model-123", "access-token-abc", LocalDateTime.now().plusDays(30), "resource-id-xyz", "resource-region-789");
        assertEquals("resource-region-789", authInfo.getResourceRegion());
    }
}
class AuthorizationGeneratorTest {
    @Test
    public void testGenerateAuthorizationInfo() {
        AuthorizationGenerator.generateAuthorizationInfo();
    }
}


import java.util.IllegalFormatException;
public class SimpleCalculator {
    public double addition(double a, double b) {
        return a + b;
    }
    public double subtraction(double a, double b) {
        return a - b;
    }
    public double multiplication(double a, double b) {
        return a * b;
    }
    public double division(double a, double b) {
        if (b == 0) {
            throw new IllegalArgumentException("除数不能为零。");
        }
        return a / b;
    }
    public static void main(String[] args) {
        SimpleCalculator calculator = new SimpleCalculator();
        System.out.println("3 + 5 = " + calculator.addition(3, 5));
        System.out.println("10 - 2 = " + calculator.subtraction(10, 2));
        System.out.println("4 * 7 = " + calculator.multiplication(4, 7));
        try {
            System.out.println("9 / 0 = " + calculator.division(9, 0));
        } catch (IllegalArgumentException e) {
            System.out.println("捕获到异常：" + e.getMessage());
        }
        check(calculator.addition(3, 5) == 8, "加法运算错误");
        check(calculator.subtraction(10, 2) == 8, "减法运算错误");
        check(calculator.multiplication(4, 7) == 28, "乘法运算错误");
        try {
            calculator.division(9, 0);
            check(false, "除法运算错误，未抛出异常");
        } catch (IllegalArgumentException e) {
            check(true, "除法运算正确");
        }
    }
    private static void check(boolean condition, String message) {
        if (!condition) {
            throw new AssertionError(message);
        }
    }
}

请编写一个Java程序，实现一个简单的计算器类`SimpleCalculator`。这个计算器需要包含四个基本的数学运算方法：加法(addition)、减法(subtraction)、乘法(multiplication)和除法(division)。每个方法接收两个`double`类型的参数，返回一个`double`类型的结果。除法方法需要处理除数为零的情况，当除数为零时，应抛出一个`IllegalArgumentException`异常。
请用Java实现不包含Main函数的完整代码，并遵循如下类型定义：

```java
import java.util.IllegalFormatException;
public class SimpleCalculator {
    public double addition(double a, double b) {
    }
    public double subtraction(double a, double b) {
    }
    public double multiplication(double a, double b) {
    }
    public double division(double a, double b) {
    }
}
```

import org.junit.jupiter.api.Test;
import static org.junit.jupiter.api.Assertions.*;
public class SimpleCalculatorTest {
    @Test
    public void testAddition() {
        SimpleCalculator calculator = new SimpleCalculator();
        assertEquals(8, calculator.addition(3, 5));
        assertEquals(0, calculator.addition(-1, 1));
        assertEquals(-3, calculator.addition(-1, -2));
    }
    @Test
    public void testSubtraction() {
        SimpleCalculator calculator = new SimpleCalculator();
        assertEquals(8, calculator.subtraction(10, 2));
        assertEquals(-2, calculator.subtraction(-1, 1));
        assertEquals(1, calculator.subtraction(0, -1));
    }
    @Test
    public void testMultiplication() {
        SimpleCalculator calculator = new SimpleCalculator();
        assertEquals(28, calculator.multiplication(4, 7));
        assertEquals(-4, calculator.multiplication(-1, 4));
        assertEquals(0, calculator.multiplication(0, 100));
    }
    @Test
    public void testDivision() {
        SimpleCalculator calculator = new SimpleCalculator();
        assertEquals(2, calculator.division(10, 5));
        assertEquals(-2, calculator.division(-4, 2));
        assertThrows(IllegalArgumentException.class, () -> {
            calculator.division(1, 0);
        });
    }
    @Test
    public void testDivisionWithZeroNumerator() {
        SimpleCalculator calculator = new SimpleCalculator();
        assertEquals(0, calculator.division(0, 5));
    }
}


import java.util.ArrayList;
import java.util.Date;
import java.util.List;
class BookLoan {
    int bookId;
    int borrowerId;
    Date borrowDate;
    public BookLoan(int bookId, int borrowerId, Date borrowDate) {
        this.bookId = bookId;
        this.borrowerId = borrowerId;
        this.borrowDate = borrowDate;
    }
}
class BookLoanDAO {
    public List<BookLoan> findAll() {
        List<BookLoan> records = new ArrayList<>();
        records.add(new BookLoan(1, 1001, new Date()));
        records.add(new BookLoan(2, 1002, new Date()));
        return records;
    }
}
class BookLoanService {
    BookLoanDAO bookLoanDAO = new BookLoanDAO();
    public List<BookLoan> fetchLoanRecordsByPage(int pageNumber, int pageSize) {
        List<BookLoan> allRecords = bookLoanDAO.findAll();
        int start = (pageNumber - 1) * pageSize;
        int end = Math.min(start + pageSize, allRecords.size());
        if (start > allRecords.size()) {
            return new ArrayList<>();
        }
        return new ArrayList<>(allRecords.subList(start, end));
    }
}
public class Main {
    public static void main(String[] args) {
        BookLoanService service = new BookLoanService();
        List<BookLoan> page1 = service.fetchLoanRecordsByPage(1, 2);
        System.out.println("第一页借阅记录数量：" + page1.size());
    }
}

请编写一个Java程序，实现一个简单的图书管理系统中的图书借阅记录分页查询功能。考虑到数据库中可能存储了大量的借阅记录，需要通过分页的方式来优化查询。每次查询返回一页的借阅记录，每页包含固定数量的记录。具体要求如下：

- 定义一个名为`BookLoan`的类，包含图书ID（`bookId`）、借阅者ID（`borrowerId`）和借阅日期（`borrowDate`）三个属性。
- 实现一个名为`BookLoanService`的类，其中包含一个方法`fetchLoanRecordsByPage`，该方法接收两个参数：`pageNumber`（当前页码）和`pageSize`（每页记录数），并返回当前页的借阅记录列表。
- 假设已有一个名为`BookLoanDAO`的类，其中包含一个方法`findAll`，该方法可以返回所有的借阅记录列表（在实际应用中，这可能是通过访问数据库获得的）。
请用Java实现不包含Main函数的完整代码，并遵循如下类型定义：

```java
import java.util.ArrayList;
import java.util.Date;
import java.util.List;
class BookLoan {
    int bookId;
    int borrowerId;
    Date borrowDate;
    public BookLoan(int bookId, int borrowerId, Date borrowDate) {
    }
}
class BookLoanDAO {
    public List<BookLoan> findAll() {
    }
}
class BookLoanService {
    BookLoanDAO bookLoanDAO = new BookLoanDAO();
    public List<BookLoan> fetchLoanRecordsByPage(int pageNumber, int pageSize) {
    }
}
```

import org.junit.jupiter.api.Assertions;
import org.junit.jupiter.api.Test;
import java.util.Date;
import java.util.List;
class BookLoanTest {
    @Test
    void testBookLoanConstructor() {
        Date now = new Date();
        BookLoan bookLoan = new BookLoan(1, 101, now);
        Assertions.assertEquals(1, bookLoan.bookId);
        Assertions.assertEquals(101, bookLoan.borrowerId);
        Assertions.assertEquals(now, bookLoan.borrowDate);
    }
}
class BookLoanDAOTest {
    @Test
    void testFindAll() {
        BookLoanDAO dao = new BookLoanDAO();
        List<BookLoan> loans = dao.findAll();
        Assertions.assertNotNull(loans);
        Assertions.assertEquals(2, loans.size());
    }
}
class BookLoanServiceTest {
    @Test
    void testFetchLoanRecordsByPage_firstPage() {
        BookLoanService service = new BookLoanService();
        List<BookLoan> page1 = service.fetchLoanRecordsByPage(1, 2);
        Assertions.assertEquals(2, page1.size());
    }
    @Test
    void testFetchLoanRecordsByPage_secondPage() {
        BookLoanService service = new BookLoanService();
        List<BookLoan> page2 = service.fetchLoanRecordsByPage(2, 2);
        Assertions.assertEquals(0, page2.size());
    }
    @Test
    void testFetchLoanRecordsByPage_invalidPage() {
        BookLoanService service = new BookLoanService();
        List<BookLoan> page = service.fetchLoanRecordsByPage(3, 2);
        Assertions.assertEquals(0, page.size());
    }
}


import java.io.IOException;
import java.util.ArrayList;
import java.util.List;
interface DatabaseAccess {
    List<String> scan(String pattern);
}
class MockDatabase implements DatabaseAccess {
    @Override
    public List<String> scan(String pattern) {
        List<String> allRecords = List.of("student:001", "student:002", "teacher:001", "student:003");
        List<String> matchedRecords = new ArrayList<>();
        for (String record : allRecords) {
            if (record.startsWith(pattern)) {
                matchedRecords.add(record);
            }
        }
        return matchedRecords;
    }
}
public class RecordFinder {
    public static List<String> findRecordsWithPrefix(DatabaseAccess databaseAccess, String prefix) {
        return databaseAccess.scan(prefix);
    }
    public static void main(String[] args) {
        MockDatabase mockDatabase = new MockDatabase();
        List<String> studentRecords = findRecordsWithPrefix(mockDatabase, "student:");
        System.out.println("找到的学生记录有: " + studentRecords);
    }
}

请编写一个Java方法，用于从一个模拟的数据库中查询出所有符合特定模式的记录。例如，我们想要查询所有以"student:"为前缀的记录。该方法应该能够高效地处理大量的数据，并确保在查询结束后释放所有资源，避免资源泄露。
请用Java实现不包含Main函数的完整代码，并遵循如下类型定义：

```java
import java.io.IOException;
import java.util.ArrayList;
import java.util.List;
interface DatabaseAccess {
    List<String> scan(String pattern);
}
class MockDatabase implements DatabaseAccess {
    @Override
    public List<String> scan(String pattern) {
    }
}
public class RecordFinder {
    public static List<String> findRecordsWithPrefix(DatabaseAccess databaseAccess, String prefix) {
    }
}
```

import org.junit.jupiter.api.Test;
import static org.junit.jupiter.api.Assertions.*;
import java.util.List;
class MockDatabaseTest {
    DatabaseAccess databaseAccess = new MockDatabase();
    @Test
    void testScanWithStudentPrefix() {
        List<String> results = databaseAccess.scan("student:");
        assertEquals(3, results.size());
        assertTrue(results.contains("student:001"));
        assertTrue(results.contains("student:002"));
        assertTrue(results.contains("student:003"));
    }
    @Test
    void testScanWithTeacherPrefix() {
        List<String> results = databaseAccess.scan("teacher:");
        assertEquals(1, results.size());
        assertTrue(results.contains("teacher:001"));
    }
    @Test
    void testScanWithEmptyPrefix() {
        List<String> results = databaseAccess.scan("");
        assertEquals(4, results.size());
        assertTrue(results.contains("student:001"));
        assertTrue(results.contains("student:002"));
        assertTrue(results.contains("teacher:001"));
        assertTrue(results.contains("student:003"));
    }
    @Test
    void testScanWithNoMatchingPrefix() {
        List<String> results = databaseAccess.scan("professor:");
        assertEquals(0, results.size());
    }
}
class RecordFinderTest {
    DatabaseAccess databaseAccess = new MockDatabase();
    @Test
    void testFindRecordsWithStudentPrefix() {
        List<String> results = RecordFinder.findRecordsWithPrefix(databaseAccess, "student:");
        assertEquals(3, results.size());
        assertTrue(results.contains("student:001"));
        assertTrue(results.contains("student:002"));
        assertTrue(results.contains("student:003"));
    }
    @Test
    void testFindRecordsWithTeacherPrefix() {
        List<String> results = RecordFinder.findRecordsWithPrefix(databaseAccess, "teacher:");
        assertEquals(1, results.size());
        assertTrue(results.contains("teacher:001"));
    }
}


import java.io.BufferedReader;
import java.io.FileReader;
import java.io.IOException;
public class TextReader {
    public String readTextWithoutNewlines(String filePath) throws IOException {
        StringBuilder contentBuilder = new StringBuilder();
        BufferedReader reader = null;
        try {
            reader = new BufferedReader(new FileReader(filePath));
            String currentLine;
            while ((currentLine = reader.readLine()) != null) {
                contentBuilder.append(currentLine);
            }
        } finally {
            if (reader != null) {
                reader.close();
            }
        }
        return contentBuilder.toString();
    }
    public static void main(String[] args) {
        TextReader reader = new TextReader();
        try {
            String result = reader.readTextWithoutNewlines("example.txt");
            System.out.println(result);
        } catch (IOException e) {
            e.printStackTrace();
        }
    }
}

请编写一个Java方法，用于从文件中读取文本内容，并移除所有的换行符（'\n'）。该方法接收一个文件路径作为参数，并返回一个不包含换行符的字符串。请确保在读取文件时正确处理资源关闭和异常。
请用Java实现不包含Main函数的完整代码，并遵循如下类型定义：

```java
import java.io.BufferedReader;
import java.io.FileReader;
import java.io.IOException;
public class TextReader {
    public String readTextWithoutNewlines(String filePath) throws IOException {
    }
}
```

import org.junit.jupiter.api.Test;
import org.junit.jupiter.api.BeforeEach;
import org.junit.jupiter.api.io.TempDir;
import java.io.BufferedWriter;
import java.io.FileWriter;
import java.io.IOException;
import java.nio.file.Path;
import static org.junit.jupiter.api.Assertions.assertEquals;
import static org.junit.jupiter.api.Assertions.assertThrows;
public class TextReaderTest {
    private TextReader textReader;
    @BeforeEach
    public void setUp() {
        textReader = new TextReader();
    }
    @TempDir
    Path tempDir;
    @Test
    public void testReadTextWithoutNewlines_singleLine() throws IOException {
        Path filePath = tempDir.resolve("singleLine.txt");
        try (BufferedWriter writer = new BufferedWriter(new FileWriter(filePath.toFile()))) {
            writer.write("This is a single line without newlines.");
        }
        String result = textReader.readTextWithoutNewlines(filePath.toString());
        assertEquals("This is a single line without newlines.", result);
    }
    @Test
    public void testReadTextWithoutNewlines_multipleLines() throws IOException {
        Path filePath = tempDir.resolve("multipleLines.txt");
        try (BufferedWriter writer = new BufferedWriter(new FileWriter(filePath.toFile()))) {
            writer.write("Line1\nLine2\nLine3\n");
        }
        String result = textReader.readTextWithoutNewlines(filePath.toString());
        assertEquals("Line1Line2Line3", result);
    }
    @Test
    public void testReadTextWithoutNewlines_fileDoesNotExist() {
        assertThrows(IOException.class, () -> {
            textReader.readTextWithoutNewlines(tempDir.resolve("nonExistentFile.txt").toString());
        });
    }
    @Test
    public void testReadTextWithoutNewlines_emptyFile() throws IOException {
        Path filePath = tempDir.resolve("emptyFile.txt");
        filePath.toFile().createNewFile();
        String result = textReader.readTextWithoutNewlines(filePath.toString());
        assertEquals("", result);
    }
    @Test
    public void testReadTextWithoutNewlines_fileWithOnlyNewlines() throws IOException {
        Path filePath = tempDir.resolve("onlyNewlines.txt");
        try (BufferedWriter writer = new BufferedWriter(new FileWriter(filePath.toFile()))) {
            writer.write("\n\n\n");
        }
        String result = textReader.readTextWithoutNewlines(filePath.toString());
        assertEquals("", result);
    }
}